1. Field of the Invention
The invention relates to a method and apparatus for liquid treatment of wafer-shaped articles.
2. Description of Related Art
Liquid treatment includes both wet etching and wet cleaning, wherein the surface area of a wafer to be treated is wetted with a treatment liquid and a layer of the wafer is thereby removed or impurities are thereby carried off. A device for liquid treatment is described in U.S. Pat. No. 4,903,717. In this device the distribution of the liquid may be assisted by the rotational motion imparted to the wafer.
Many of the processes performed on such devices require heat to be applied to the wafer. Commonly-owned copending application US 2013/0061873 describes such a device in which a heating assembly is mounted in a stationary manner on a central post about which a rotary chuck rotates. A wafer is held on this device above the heating assembly by a series of gripping pins that project upwardly from the periphery of the chuck. Consequently, the heating assembly must be positioned entirely within the central region delimited by the pin assemblies, which limits the ability of the heating assembly to heat the wafer at its outer edge region.